An LED (Light Emitting Device) is a semiconductor device to convert electrical energy into light energy and can reproduce light of various wavelengths such as red, green, blue, and ultraviolet by controlling a composition of a compound semiconductor, and can emit white light by using a fluorescent material or combining colors with each other.
When comparing with conventional light sources such as a fluorescent lamp, and an incandescent lamp, the semiconductor light emitting device has advantages such as low power consumption, a semi-permanent life span, a rapid response speed, safety, and an eco-friendly property. The application of the semiconductor light emitting device is expanded to a light emitting diode backlight serving as a substitute for a CCFL (Cold Cathode Fluorescence Lamp) constituting a backlight of an LCD (Liquid Crystal Display), a white light emitting diode lighting device serving as a substitute for the fluorescent lamp or the incandescent lamp, a vehicle headlight, and a signal lamp.
In a light emitting device package according to the related art, a light emitting device is mounted on a package body, and an electrode layer is formed on the package body so as to be electrically connected to the light emitting device. Further, a molding part having a luminescence material is formed on the light emitting device.
The light emitting device according to the related art is weak against electrostatic discharge (ESD). In order to complement the above weakness, a zener diode is mounted together with an LED chip to prevent the ESD.
However, the zener diode mounted on an electrode together with the LED chip in order to improve ESD characteristics absorbs a part of light emitted from the LED chip so that light efficiency is lowered.
For example, according to the related art, the zener diode to prevent the ESD is manufactured by using silicon. Since an energy bandgap of the silicon is about 1.12 eV and the energy of a photon emitted from UV˜Visible (200 nm-680 nm) LED is in the range of about 1.8 eV to about 6.2 eV significantly higher than the energy bandgap of the silicon, the zener diode having the small energy bandgap absorbs a large amount of light so that light extraction efficiency is lowered.
Moreover, according to the related art, a part of light emitted from the LED chip is absorbed in an electrode exposed on the package body so that the light extraction efficiency is lowered.